1. Field of the Invention
This invention relates to paste-dispensing toothbrushes and, more specifically, to such toothbrushes in which the paste reservoir is manually varied in volume and may be re-filled.
2. Prior Art
A search of the related sub-classes in the files of the U.S. Patent and Trademark Office revealed the following U.S. patents which are of interest but from which the present invention may be distinguished:
U.S. Pat. No. 1,192,668 (Miles) PA1 U.S. Pat. No. 1,944,067 (Collins) PA1 U.S. Pat. No. 2,814,816 (Pepping, et al) PA1 U.S. Pat. No. 3,256,893 (Mc Eachran) PA1 U.S. Pat. No. 2,278,253 (Ellsworth) PA1 French Pat. No. 810,644 (Lavaud)
The Miles patent requires an adapter 26 to couple a toothpaste tube to the flexible tube 18. Such an adapter will invariably be lost by the user rendering the brush useless. Further, flexible tube 18 is twisted by knob 24 to cause toothpaste to be expelled through discharge opening 12. Repeated twisting of tube 18 will cause it to deteriorate rendering the brush of Miles short lived.
The Collins patent, in FIGS. 1-12, is directed to a non-refillable toothbrush. This invention relates to a re-fillable toothbrush. In FIGS. 13-17 Collins shows a re-fillable toothbrush but in each case the toothbrush reservoir has a female connector adapted to engage the male threads on a toothpaste tube nozzle. I have discovered that outer diameters of tube nozzles or spouts vary widely, but inner diameters are standard. Thus, Collins' toothbrush could be filled with a limited line of toothpastes, whereas the brush described in this application could be filled from any toothpaste tube containing toothpaste.
The Pepping patent is directed to a toothbrush with a pressurized cartridge containing toothpaste. It is not a refillable reservoir. Thus its cost is high and its chances for commercial success are low.
The Mc Eachran patent is also directed to a toothbrush in which the paste is moved by a propellant. Relatively movable tubes expose dentifrice escape openings. The device of this patent is relatively complex and expensive to build, in contrast to the practical configuration presented in the present application.
The Ellsworth patent shows a complex and economically impractical structure which again suffers from its inability to be loaded from any toothpaste tube because the patent teaches coupling to the outer threads of the tube, which threads vary in diameter between manufacturers. In my device the structure is significantly simplified by using the body itself as the means for driving the piston forward and backward in addition to assuring universal coupling to toothpaste tubes.
The French patent to Lavaud suffers from the same coupling problem as was described earlier when re-filling from a tube is desired. Further, the helical structure of FIG. 1 is unnecessarily complex and expensive to build.
It is an object of this invention to overcome the problems and disadvantages of the prior art devices.
It is a further object of the present invention to provide an improved paste-dispensing toothbrush which may be re-filled from any available toothpaste tube.